DOWNHOLE TOOLS WITH INDEPENDENTLY-OPERATED CUTTERS AND METHODS OF MILLING LONG SECTIONS OF A CASING THEREWITH

摘要

In one aspect, an apparatus for use in a wellbore is disclosed that in one non-limiting embodiment includes a plurality of cutters, each cutter having expandable cutting elements, a control unit associated with each cutter to expand the cutting elements of its associated cutter and a controller that controls each of the control units to independently activate and deactivate each cutter in the plurality of cutters to expand the cutting elements of each such cutter.